Polymers of alpha-piperidone



United States Patent POLYMERS or ALPHA-Pneumonia Carl E. Barnes,Gloucester, William R. Nurnmy, Warren, and William 0. Ney, .l'r.,Providence, R. 5., assignors to Arnold, Hofiman & (30., Incorporated,Providence, R. L, a corporation of Rhode Island N0 Drawing. ApplicationFebruary 24, 1953, Serial No. 338,555

5 Claims. (Cl. 26fi78) This invention relates to the production of newand useful organic polymers from a piperidone.

Heretofore the teachings in the literature have been to the effect thatpolymerization of this compound did not take place.

We have discovered that a piperidone can be successfully polymerized toproduce a useful high molecular weight product which we identity aspolypiperidone.

This discovery is unexpected because six-membered lactams werepreviously considered unpolymeris'able, and consequently the method wastried on 0: piperidone, the simplest example. The compound was found tobe more difiicult to polymerize than a five-membered lactam e. g.,pyrrolidone, and actually required the addition of a very strongactivator to the potassium hydroxide treated reaction mixture. Apolymeric substance exhibiting the properties of a polyamide wasisolated and its composition confirmed by carbon, hydrogen and nitrogenanalysis which approximated the theoretical values for a polymer ofpipen'done.

It is the object of this invention to provide a new polyamide based ono: piperidone, and a method for its production.

Carefully purified cc piperidone is treated with potassium hydroxide anda portion distilled under vacuum to insure removal of the water formed.An activator, e. g., an acyl halide such as acetyl chloride, pelargonylchloride, stearolyl chloride, is then added in weight equivalent to 25to 50 percent of the potassium hydroxide added originally. An immediateexothermic reaction occurs, the reaction mixture is treated with waterand the insoluble polymer is isolated as a nearly-white powder. It canbe melted and forms into a tough, horny mass on cooling. It has many ofthe desirable properties of polyamides. It is useful as a molding powderfrom which useful objects can be prepared by compression molding i. e.,heat and pressure or pressure alone.

Example Purified a piperidone, 71 parts, are treated with 1.5 partspotassium hydroxide pellets in a suitable vessel fitted for stirring,vacuum distillation, and an inlet for dry nitrogen gas when required.Piperidone, parts, are removed by vacuum distillation.

The resulting reaction mixture remaining in the vessel, 57.5 parts, istreated with 0.7 parts of benzoyl chloride, under an atmosphere of drynitrogen. The mixture sets up rapidly to a thick slurry. After standingfor 24 hours, the slurry was thoroughly mixed with about five times itsvolume of water, and the insoluble polymer filtered off on a suctionfilter. The resulting nearly white powder is sucked dry and furtherdried in a vacuum oven at 70 C. A very satisfactory molding powder isthus produced. If desired the polymer may be removed from the filter asa dry cake or coarse granules.

Faiented Sept. 17, 1957 This application is a continuation in part ofour application No. 260,558, filed December 7, 1951, which describes thepolymerization of five and six membered rings including deltavalerolactam or on piperidone, and the polymer thereof may be" employedas described in said application. The latter has now issued as U. S.Patent 2,638,463 of May 12, 1953.

This new polymer, as typified by polypiperidone, is produced either as adry cake; in the form of coarse granules; or as a fine molding powderand has many desirable properties. For example, polypiperidone isthermoplastic. It may be combined with suitable fillers or extenders andother conventional constituents, e. g., plasticizers, solvents, pigmentsdyes, etc, and shaped; spread or cast as a film or surface coating; usedas an impregnant, and can be extruded, for instance, as fibres orfilaments and films or sheets. It may be solvent spun by either wet ordry spinning to form fibres.

Instead of potassium hydroxide, potassium itself may be employed asdescribed in United States Patent 2,638,463 as well as sodium andlithium and corresponding salts of the various metals, e. g., carbonatesas well as hydroxides and oxides of the alkali metals and all othercatalysts all as described in our said application which is herebyincorporated as a part of this patent specification and disclosure.

In addition to the activator mentioned, benzoyl chloride, :others may beemployed as described in our application filed concurrently herewith anddirected to the use of activators for speeding up and increasing theyield of the polymerization reaction.

The proportions described above are subject to variation as described in.our said applications and as also described therein, thepolymerization; reaction is carried at temperatures between 0 and 300 C.

The polymerization may also be carried out in the presence of a nonsolvent for the lactam monomer and polymer, e. g., petroleum ether,gasoline, etc., as described in the application of Ney and Crowtherfiled concurrently herewith, now U. 5. Patent No. 2,739,959 whichdisclosure is hereby incorporated in the specification and disclosure ofthis application.

We claim:

1. Fiber-forming homo-polymers of a-piperidone consisting essentially ofthe recurring unit 2. The process which comprises polymerizingu-piperidone in the presence of an alkaline polymerization catalystmixture comprising an inorganic alkaline substance and an acyl groupcontaining activator therefor.

3. A process according to claim 2 wherein the activator is an acylhalide.

4. A filament comprising the polymer of claim 1.

5. A film comprising the polymer of claim 1.

References Cited in the file of this patent UNITED STATES PATENTS2,293,388 Hanford Aug. 18, 1942 2,739,959 Ney et al. Mar. 27, 1956FOREIGN PATENTS 739,953 Germany Oct. 26, 1943 OTHER REFERENCES Leimu etal: Suomen Kemistilehti, vol. 18B, pages 40 to 43, (1945).

1. FIBER-FORMING HOMO-POLYMERS OF A-PIPERIDONE CONSISTING ESSENTIALLY OFTHE RECURRING UNIT